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Diffstat (limited to 'src/resolve/resolved-dns-scope.c')
-rw-r--r--src/resolve/resolved-dns-scope.c323
1 files changed, 247 insertions, 76 deletions
diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 9e6f595a1b..8a52d66fad 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -21,15 +21,18 @@
#include <netinet/tcp.h>
-#include "missing.h"
-#include "strv.h"
-#include "socket-util.h"
#include "af-list.h"
-#include "random-util.h"
-#include "hostname-util.h"
+#include "alloc-util.h"
#include "dns-domain.h"
-#include "resolved-llmnr.h"
+#include "fd-util.h"
+#include "hostname-util.h"
+#include "missing.h"
+#include "random-util.h"
#include "resolved-dns-scope.h"
+#include "resolved-llmnr.h"
+#include "resolved-mdns.h"
+#include "socket-util.h"
+#include "strv.h"
#define MULTICAST_RATELIMIT_INTERVAL_USEC (1*USEC_PER_SEC)
#define MULTICAST_RATELIMIT_BURST 1000
@@ -54,9 +57,25 @@ int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int
s->family = family;
s->resend_timeout = MULTICAST_RESEND_TIMEOUT_MIN_USEC;
+ s->dnssec_mode = _DNSSEC_MODE_INVALID;
+
+ if (protocol == DNS_PROTOCOL_DNS) {
+ /* Copy DNSSEC mode from the link if it is set there,
+ * otherwise take the manager's DNSSEC mode. Note that
+ * we copy this only at scope creation time, and do
+ * not update it from the on, even if the setting
+ * changes. */
+
+ if (l)
+ s->dnssec_mode = link_get_dnssec_mode(l);
+ else
+ s->dnssec_mode = manager_get_dnssec_mode(m);
+ }
+
LIST_PREPEND(scopes, m->dns_scopes, s);
dns_scope_llmnr_membership(s, true);
+ dns_scope_mdns_membership(s, true);
log_debug("New scope on link %s, protocol %s, family %s", l ? l->name : "*", dns_protocol_to_string(protocol), family == AF_UNSPEC ? "*" : af_to_name(family));
@@ -67,29 +86,40 @@ int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int
return 0;
}
-DnsScope* dns_scope_free(DnsScope *s) {
- DnsTransaction *t;
- DnsResourceRecord *rr;
-
- if (!s)
- return NULL;
-
- log_debug("Removing scope on link %s, protocol %s, family %s", s->link ? s->link->name : "*", dns_protocol_to_string(s->protocol), s->family == AF_UNSPEC ? "*" : af_to_name(s->family));
+static void dns_scope_abort_transactions(DnsScope *s) {
+ assert(s);
- dns_scope_llmnr_membership(s, false);
+ while (s->transactions) {
+ DnsTransaction *t = s->transactions;
- while ((t = hashmap_steal_first(s->transactions))) {
/* Abort the transaction, but make sure it is not
* freed while we still look at it */
t->block_gc++;
- dns_transaction_complete(t, DNS_TRANSACTION_ABORTED);
+ if (DNS_TRANSACTION_IS_LIVE(t->state))
+ dns_transaction_complete(t, DNS_TRANSACTION_ABORTED);
t->block_gc--;
dns_transaction_free(t);
}
+}
+
+DnsScope* dns_scope_free(DnsScope *s) {
+ DnsResourceRecord *rr;
- hashmap_free(s->transactions);
+ if (!s)
+ return NULL;
+
+ log_debug("Removing scope on link %s, protocol %s, family %s", s->link ? s->link->name : "*", dns_protocol_to_string(s->protocol), s->family == AF_UNSPEC ? "*" : af_to_name(s->family));
+
+ dns_scope_llmnr_membership(s, false);
+ dns_scope_mdns_membership(s, false);
+ dns_scope_abort_transactions(s);
+
+ while (s->query_candidates)
+ dns_query_candidate_free(s->query_candidates);
+
+ hashmap_free(s->transactions_by_key);
while ((rr = ordered_hashmap_steal_first(s->conflict_queue)))
dns_resource_record_unref(rr);
@@ -101,7 +131,6 @@ DnsScope* dns_scope_free(DnsScope *s) {
dns_zone_flush(&s->zone);
LIST_REMOVE(scopes, s->manager->dns_scopes, s);
- strv_free(s->domains);
free(s);
return NULL;
@@ -134,11 +163,11 @@ void dns_scope_next_dns_server(DnsScope *s) {
void dns_scope_packet_received(DnsScope *s, usec_t rtt) {
assert(s);
- if (rtt > s->max_rtt) {
- s->max_rtt = rtt;
- s->resend_timeout = MIN(MAX(MULTICAST_RESEND_TIMEOUT_MIN_USEC, s->max_rtt * 2),
- MULTICAST_RESEND_TIMEOUT_MAX_USEC);
- }
+ if (rtt <= s->max_rtt)
+ return;
+
+ s->max_rtt = rtt;
+ s->resend_timeout = MIN(MAX(MULTICAST_RESEND_TIMEOUT_MIN_USEC, s->max_rtt * 2), MULTICAST_RESEND_TIMEOUT_MAX_USEC);
}
void dns_scope_packet_lost(DnsScope *s, usec_t usec) {
@@ -148,17 +177,15 @@ void dns_scope_packet_lost(DnsScope *s, usec_t usec) {
s->resend_timeout = MIN(s->resend_timeout * 2, MULTICAST_RESEND_TIMEOUT_MAX_USEC);
}
-int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) {
+static int dns_scope_emit_one(DnsScope *s, int fd, DnsPacket *p) {
union in_addr_union addr;
int ifindex = 0, r;
int family;
- uint16_t port;
uint32_t mtu;
assert(s);
assert(p);
assert(p->protocol == s->protocol);
- assert((s->protocol == DNS_PROTOCOL_DNS) != (fd < 0));
if (s->link) {
mtu = s->link->mtu;
@@ -167,7 +194,10 @@ int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) {
mtu = manager_find_mtu(s->manager);
switch (s->protocol) {
+
case DNS_PROTOCOL_DNS:
+ assert(fd >= 0);
+
if (DNS_PACKET_QDCOUNT(p) > 1)
return -EOPNOTSUPP;
@@ -184,6 +214,8 @@ int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) {
break;
case DNS_PROTOCOL_LLMNR:
+ assert(fd < 0);
+
if (DNS_PACKET_QDCOUNT(p) > 1)
return -EOPNOTSUPP;
@@ -191,7 +223,6 @@ int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) {
return -EBUSY;
family = s->family;
- port = LLMNR_PORT;
if (family == AF_INET) {
addr.in = LLMNR_MULTICAST_IPV4_ADDRESS;
@@ -204,7 +235,32 @@ int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) {
if (fd < 0)
return fd;
- r = manager_send(s->manager, fd, ifindex, family, &addr, port, p);
+ r = manager_send(s->manager, fd, ifindex, family, &addr, LLMNR_PORT, p);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case DNS_PROTOCOL_MDNS:
+ assert(fd < 0);
+
+ if (!ratelimit_test(&s->ratelimit))
+ return -EBUSY;
+
+ family = s->family;
+
+ if (family == AF_INET) {
+ addr.in = MDNS_MULTICAST_IPV4_ADDRESS;
+ fd = manager_mdns_ipv4_fd(s->manager);
+ } else if (family == AF_INET6) {
+ addr.in6 = MDNS_MULTICAST_IPV6_ADDRESS;
+ fd = manager_mdns_ipv6_fd(s->manager);
+ } else
+ return -EAFNOSUPPORT;
+ if (fd < 0)
+ return fd;
+
+ r = manager_send(s->manager, fd, ifindex, family, &addr, MDNS_PORT, p);
if (r < 0)
return r;
@@ -217,8 +273,39 @@ int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) {
return 1;
}
-static int dns_scope_socket(DnsScope *s, int type, int family, const union in_addr_union *address, uint16_t port, DnsServer **server) {
- DnsServer *srv = NULL;
+int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p) {
+ int r;
+
+ assert(s);
+ assert(p);
+ assert(p->protocol == s->protocol);
+ assert((s->protocol == DNS_PROTOCOL_DNS) == (fd >= 0));
+
+ do {
+ /* If there are multiple linked packets, set the TC bit in all but the last of them */
+ if (p->more) {
+ assert(p->protocol == DNS_PROTOCOL_MDNS);
+ dns_packet_set_flags(p, true, true);
+ }
+
+ r = dns_scope_emit_one(s, fd, p);
+ if (r < 0)
+ return r;
+
+ p = p->more;
+ } while (p);
+
+ return 0;
+}
+
+static int dns_scope_socket(
+ DnsScope *s,
+ int type,
+ int family,
+ const union in_addr_union *address,
+ DnsServer *server,
+ uint16_t port) {
+
_cleanup_close_ int fd = -1;
union sockaddr_union sa = {};
socklen_t salen;
@@ -226,26 +313,27 @@ static int dns_scope_socket(DnsScope *s, int type, int family, const union in_ad
int ret, r;
assert(s);
- assert((family == AF_UNSPEC) == !address);
- if (family == AF_UNSPEC) {
- srv = dns_scope_get_dns_server(s);
- if (!srv)
- return -ESRCH;
+ if (server) {
+ assert(family == AF_UNSPEC);
+ assert(!address);
- sa.sa.sa_family = srv->family;
- if (srv->family == AF_INET) {
+ sa.sa.sa_family = server->family;
+ if (server->family == AF_INET) {
sa.in.sin_port = htobe16(port);
- sa.in.sin_addr = srv->address.in;
+ sa.in.sin_addr = server->address.in;
salen = sizeof(sa.in);
- } else if (srv->family == AF_INET6) {
+ } else if (server->family == AF_INET6) {
sa.in6.sin6_port = htobe16(port);
- sa.in6.sin6_addr = srv->address.in6;
+ sa.in6.sin6_addr = server->address.in6;
sa.in6.sin6_scope_id = s->link ? s->link->ifindex : 0;
salen = sizeof(sa.in6);
} else
return -EAFNOSUPPORT;
} else {
+ assert(family != AF_UNSPEC);
+ assert(address);
+
sa.sa.sa_family = family;
if (family == AF_INET) {
@@ -303,36 +391,34 @@ static int dns_scope_socket(DnsScope *s, int type, int family, const union in_ad
if (r < 0 && errno != EINPROGRESS)
return -errno;
- if (server)
- *server = srv;
-
ret = fd;
fd = -1;
return ret;
}
-int dns_scope_udp_dns_socket(DnsScope *s, DnsServer **server) {
- return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, 53, server);
+int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port) {
+ return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, server, port);
}
-int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *address, uint16_t port, DnsServer **server) {
- return dns_scope_socket(s, SOCK_STREAM, family, address, port, server);
+int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port) {
+ return dns_scope_socket(s, SOCK_STREAM, family, address, server, port);
}
DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain) {
- char **i;
+ DnsSearchDomain *d;
assert(s);
assert(domain);
- if (ifindex != 0 && (!s->link || s->link->ifindex != ifindex))
- return DNS_SCOPE_NO;
+ /* Checks if the specified domain is something to look up on
+ * this scope. Note that this accepts non-qualified hostnames,
+ * i.e. those without any search path prefixed yet. */
- if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family) & flags) == 0)
+ if (ifindex != 0 && (!s->link || s->link->ifindex != ifindex))
return DNS_SCOPE_NO;
- if (dns_name_root(domain) != 0)
+ if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family, 0) & flags) == 0)
return DNS_SCOPE_NO;
/* Never resolve any loopback hostname or IP address via DNS,
@@ -343,15 +429,38 @@ DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, co
dns_name_equal(domain, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0)
return DNS_SCOPE_NO;
- STRV_FOREACH(i, s->domains)
- if (dns_name_endswith(domain, *i) > 0)
+ /* Never respond to some of the domains listed in RFC6303 */
+ if (dns_name_endswith(domain, "0.in-addr.arpa") > 0 ||
+ dns_name_equal(domain, "255.255.255.255.in-addr.arpa") > 0 ||
+ dns_name_equal(domain, "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0)
+ return DNS_SCOPE_NO;
+
+ /* Never respond to some of the domains listed in RFC6761 */
+ if (dns_name_endswith(domain, "invalid") > 0)
+ return DNS_SCOPE_NO;
+
+ /* Always honour search domains for routing queries. Note that
+ * we return DNS_SCOPE_YES here, rather than just
+ * DNS_SCOPE_MAYBE, which means wildcard scopes won't be
+ * considered anymore. */
+ LIST_FOREACH(domains, d, dns_scope_get_search_domains(s))
+ if (dns_name_endswith(domain, d->name) > 0)
return DNS_SCOPE_YES;
switch (s->protocol) {
+
case DNS_PROTOCOL_DNS:
+
+ /* Exclude link-local IP ranges */
if (dns_name_endswith(domain, "254.169.in-addr.arpa") == 0 &&
- dns_name_endswith(domain, "0.8.e.f.ip6.arpa") == 0 &&
- dns_name_single_label(domain) == 0)
+ dns_name_endswith(domain, "8.e.f.ip6.arpa") == 0 &&
+ dns_name_endswith(domain, "9.e.f.ip6.arpa") == 0 &&
+ dns_name_endswith(domain, "a.e.f.ip6.arpa") == 0 &&
+ dns_name_endswith(domain, "b.e.f.ip6.arpa") == 0 &&
+ /* If networks use .local in their private setups, they are supposed to also add .local to their search
+ * domains, which we already checked above. Otherwise, we consider .local specific to mDNS and won't
+ * send such queries ordinary DNS servers. */
+ dns_name_endswith(domain, "local") == 0)
return DNS_SCOPE_MAYBE;
return DNS_SCOPE_NO;
@@ -369,7 +478,7 @@ DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, co
case DNS_PROTOCOL_LLMNR:
if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) ||
(s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) ||
- (dns_name_single_label(domain) > 0 && /* only resolve single label names via LLMNR */
+ (dns_name_is_single_label(domain) && /* only resolve single label names via LLMNR */
!is_gateway_hostname(domain) && /* don't resolve "gateway" with LLMNR, let nss-myhostname handle this */
manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via LLMNR */
return DNS_SCOPE_MAYBE;
@@ -385,8 +494,27 @@ int dns_scope_good_key(DnsScope *s, DnsResourceKey *key) {
assert(s);
assert(key);
- if (s->protocol == DNS_PROTOCOL_DNS)
- return true;
+ /* Check if it makes sense to resolve the specified key on
+ * this scope. Note that this call assumes as fully qualified
+ * name, i.e. the search suffixes already appended. */
+
+ if (s->protocol == DNS_PROTOCOL_DNS) {
+
+ /* On classic DNS, looking up non-address RRs is always
+ * fine. (Specifically, we want to permit looking up
+ * DNSKEY and DS records on the root and top-level
+ * domains.) */
+ if (!dns_resource_key_is_address(key))
+ return true;
+
+ /* However, we refuse to look up A and AAAA RRs on the
+ * root and single-label domains, under the assumption
+ * that those should be resolved via LLMNR or search
+ * path only, and should not be leaked onto the
+ * internet. */
+ return !(dns_name_is_single_label(DNS_RESOURCE_KEY_NAME(key)) ||
+ dns_name_is_root(DNS_RESOURCE_KEY_NAME(key)));
+ }
/* On mDNS and LLMNR, send A and AAAA queries only on the
* respective scopes */
@@ -400,19 +528,15 @@ int dns_scope_good_key(DnsScope *s, DnsResourceKey *key) {
return true;
}
-int dns_scope_llmnr_membership(DnsScope *s, bool b) {
+static int dns_scope_multicast_membership(DnsScope *s, bool b, struct in_addr in, struct in6_addr in6) {
int fd;
assert(s);
-
- if (s->protocol != DNS_PROTOCOL_LLMNR)
- return 0;
-
assert(s->link);
if (s->family == AF_INET) {
struct ip_mreqn mreqn = {
- .imr_multiaddr = LLMNR_MULTICAST_IPV4_ADDRESS,
+ .imr_multiaddr = in,
.imr_ifindex = s->link->ifindex,
};
@@ -431,7 +555,7 @@ int dns_scope_llmnr_membership(DnsScope *s, bool b) {
} else if (s->family == AF_INET6) {
struct ipv6_mreq mreq = {
- .ipv6mr_multiaddr = LLMNR_MULTICAST_IPV6_ADDRESS,
+ .ipv6mr_multiaddr = in6,
.ipv6mr_interface = s->link->ifindex,
};
@@ -450,6 +574,22 @@ int dns_scope_llmnr_membership(DnsScope *s, bool b) {
return 0;
}
+int dns_scope_llmnr_membership(DnsScope *s, bool b) {
+
+ if (s->protocol != DNS_PROTOCOL_LLMNR)
+ return 0;
+
+ return dns_scope_multicast_membership(s, b, LLMNR_MULTICAST_IPV4_ADDRESS, LLMNR_MULTICAST_IPV6_ADDRESS);
+}
+
+int dns_scope_mdns_membership(DnsScope *s, bool b) {
+
+ if (s->protocol != DNS_PROTOCOL_MDNS)
+ return 0;
+
+ return dns_scope_multicast_membership(s, b, MDNS_MULTICAST_IPV4_ADDRESS, MDNS_MULTICAST_IPV6_ADDRESS);
+}
+
static int dns_scope_make_reply_packet(
DnsScope *s,
uint16_t id,
@@ -500,7 +640,7 @@ static int dns_scope_make_reply_packet(
if (answer) {
for (i = 0; i < answer->n_rrs; i++) {
- r = dns_packet_append_rr(p, answer->items[i].rr, NULL);
+ r = dns_packet_append_rr(p, answer->items[i].rr, NULL, NULL);
if (r < 0)
return r;
}
@@ -510,7 +650,7 @@ static int dns_scope_make_reply_packet(
if (soa) {
for (i = 0; i < soa->n_rrs; i++) {
- r = dns_packet_append_rr(p, soa->items[i].rr, NULL);
+ r = dns_packet_append_rr(p, soa->items[i].rr, NULL, NULL);
if (r < 0)
return r;
}
@@ -541,6 +681,7 @@ static void dns_scope_verify_conflicts(DnsScope *s, DnsPacket *p) {
void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) {
_cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL;
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL;
+ DnsResourceKey *key = NULL;
bool tentative = false;
int r, fd;
@@ -574,7 +715,10 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) {
return;
}
- r = dns_zone_lookup(&s->zone, p->question, &answer, &soa, &tentative);
+ assert(p->question->n_keys == 1);
+ key = p->question->keys[0];
+
+ r = dns_zone_lookup(&s->zone, key, &answer, &soa, &tentative);
if (r < 0) {
log_debug_errno(r, "Failed to lookup key: %m");
return;
@@ -632,15 +776,15 @@ DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key,
/* Try to find an ongoing transaction that is a equal to the
* specified question */
- t = hashmap_get(scope->transactions, key);
+ t = hashmap_get(scope->transactions_by_key, key);
if (!t)
return NULL;
/* Refuse reusing transactions that completed based on cached
* data instead of a real packet, if that's requested. */
if (!cache_ok &&
- IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_FAILURE) &&
- !t->received)
+ IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_RCODE_FAILURE) &&
+ t->answer_source != DNS_TRANSACTION_NETWORK)
return NULL;
return t;
@@ -672,7 +816,11 @@ static int dns_scope_make_conflict_packet(
0 /* (ad) */,
0 /* (cd) */,
0));
- random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t));
+
+ /* For mDNS, the transaction ID should always be 0 */
+ if (s->protocol != DNS_PROTOCOL_MDNS)
+ random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t));
+
DNS_PACKET_HEADER(p)->qdcount = htobe16(1);
DNS_PACKET_HEADER(p)->arcount = htobe16(1);
@@ -680,7 +828,7 @@ static int dns_scope_make_conflict_packet(
if (r < 0)
return r;
- r = dns_packet_append_rr(p, rr, NULL);
+ r = dns_packet_append_rr(p, rr, NULL, NULL);
if (r < 0)
return r;
@@ -713,7 +861,7 @@ static int on_conflict_dispatch(sd_event_source *es, usec_t usec, void *userdata
return 0;
}
- r = dns_scope_emit(scope, -1, p);
+ r = dns_scope_emit_udp(scope, -1, p);
if (r < 0)
log_debug_errno(r, "Failed to send conflict packet: %m");
}
@@ -762,6 +910,8 @@ int dns_scope_notify_conflict(DnsScope *scope, DnsResourceRecord *rr) {
if (r < 0)
return log_debug_errno(r, "Failed to add conflict dispatch event: %m");
+ (void) sd_event_source_set_description(scope->conflict_event_source, "scope-conflict");
+
return 0;
}
@@ -844,3 +994,24 @@ void dns_scope_dump(DnsScope *s, FILE *f) {
dns_cache_dump(&s->cache, f);
}
}
+
+DnsSearchDomain *dns_scope_get_search_domains(DnsScope *s) {
+ assert(s);
+
+ if (s->protocol != DNS_PROTOCOL_DNS)
+ return NULL;
+
+ if (s->link)
+ return s->link->search_domains;
+
+ return s->manager->search_domains;
+}
+
+bool dns_scope_name_needs_search_domain(DnsScope *s, const char *name) {
+ assert(s);
+
+ if (s->protocol != DNS_PROTOCOL_DNS)
+ return false;
+
+ return dns_name_is_single_label(name);
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-12-12 00:38:35 +0000